The invention relates to machine tools and in particular to lathe tools, specifically it relates to chucks.
A need has existed for an improved chuck for machining work-pieces of disc-like configuration from very thin thicknesses to rather heavy thicknesses. This invention provides such a chuck that can machine pieces essentially from sheet metal type stock to thicknesses up to the limit of the lathe capacity from chuck to the tail stock.
In the prior art thin work pieces, and in some cases thicker work pieces, had to be machined by trepanning. For work-pieces that were thick enough to grasp in a three-jaw chuck and still have room to perform a portion of the machine work, the prior art required two set-ups. First, in a three-jaw to do a portion of the work, then removing the work piece, turning it around and placing it in a four-jaw chuck to finish the machine work.
The above operations are time consuming, require exacting detail set-up, and can be hazardous. The present invention eliminates these problems.
The present invention provides a disc-like chuck with tooth-like projections around the periphery, and a removable centering piece at the center thereof. The improved chuck is held in an ordinary three-jaw chuck in a lathe when in use. The work piece is centered on the improved chuck on the side with the tooth-like projections and then held in place there by the pressure of a rotating bull-nose tailstock. The bull-nose tailstock pressure is applied through a rubber-like disc on the disc-like end of the bull-nose tailstock.
The improved chuck permits machining the outside surface with the single set-up.
The centering piece of the improved chuck assists in centering the work piece when the outside surface is to be machined concentric with a hole at the center of the work piece disc.
It is, therefore, an object of the invention to provide a chuck for machine operations that can hold a disc-like work piece for machine operations on the exterior surface in a single set-up.
It is another object of the invention to provide a chuck for machine operations that can center a disc-like work piece for machining an external surface concentric with a hole at the center of said work piece.
It is still another object of the invention to provide a chuck for machine operations wherein the disc-like work piece is held to the chuck by pressure applied by a rotating bull-nose tailstock.
It is yet another object of the invention to provide a chuck for machine operations that eliminates the hazards of the prior art.
Further objects and advantages of the invention will become more apparent in light of the following description of the preferred embodiment.